Effect of prescribed burning and vegetation thinning at the Little River Adaptive Management Area (BLM 2002) Seed biology studies and germination trials indicate that germination is stimulated by a long (12-14 week) period of cold, moist, dark stratification. This ensures that seeds only germinate in the spring, following the cold winter (Florance 1994).

In a three-year comparative demographic study, permanent plots were monitored at five sites comprising three different habitat types for C. umpquaensis and at two sites for C. coxii. Bud production was highest and plants were most dense and larger on average in the ecotone habitat (area between grassland and forest). Individual growth rates were higher among C. umpquaensis than among C. coxii, and it was less habitat-specific, suggesting that it is able to colonize. Transition matrix models indicated that the populations studied are projected to be stable rather than increasing or decreasing (Fredricks 1992). Demographic comparisons using matrix models were made between eight closely related species from the Calochortus genus. Results indicated that matrix models do not give a complete picture of population dynamics. Population distribution (proportion of seedlings, juveniles, and reproductive adults) were highly variable between population, habitats, and years. For most species, including C. umpquaensis, there was a lower proportion of juvenile plants than the model predicted. Reproduction was most limiting to population growth and more variable, and perhaps less predictable than was mortality. Reproductive output varied considerably across habitats (Feidler et al. 1998).

Seed from 4 locations stored at The Berry Botanic Garden.

Seed from 4 locations stored at The Berry Botanic Garden.

Largely restricted to serpentine soils in the Umpqua River drainage, Douglas County, southwestern Oregon, with two small outlying occurrences known from adjacent Josephine and Jackson counties. Approximately 14-17 occurrences are believed extant; two of these are located on private lands, with the remainder relatively evenly split between Bureau of Land Management (BLM) and U.S. Forest Service (USFS)-managed lands. Many of the occurrences are somewhat small, but several contain thousands of individuals, and one on BLM lands is reported to harbor an estimated 400,000 - 800,000 individuals. In the mid-1990s, logging and cattle grazing were believed to be significant threats. However, in 1996, a conservation agreement was signed by the BLM, USFS, and U.S. Fish and Wildlife Service that addressed these two issues, at least on public lands. Other threats include significant consumption of reproductive structures by native herbivores (e.g. deer) at some sites, competition from weedy non-native species, bulb collection, potentially reduced habitat quality due to fire suppression, and the potential for mining of the nickel-rich soils in which the plant occurs.

Grazing (Fredricks 1989) Logging and road construction (Fredricks 1989) Bulb digging by collectors (Fredricks 1989) Nickel mining (Fredricks 1989) Competition from non-native vegetation

2000: 14 populations (4 on BLM land), estimated 400,000 to 800,000 individuals on BLM land (USFWS 2000).

Effect of prescribed burning and vegetation thinning at the Little River Adaptive Management Area (BLM 2002) Seed biology studies and germination trials indicate that germination is stimulated by a long (12-14 week) period of cold, moist, dark stratification. This ensures that seeds only germinate in the spring, following the cold winter (Florance 1994). Germination trials at The Berry Botanic Garden obtained 100% germination after 8 weeks of cold stratification followed by a constant 68F (20C) or alternating 50F/68F (10/20C) environment (BBG File). In a three-year comparative demographic study, permanent plots were monitored at five sites comprising three different habitat types for C. umpquaensis and at two sites for C. coxii. Bud production was highest and plants were most dense and larger on average in the ecotone habitat (area between grassland and forest). Individual growth rates were higher among C. umpquaensis than among C. coxii, and it was less habitat-specific, suggesting that it is able to colonize. Transition matrix models indicated that the populations studied are projected to be stable rather than increasing or decreasing (Fredricks 1992). Demographic comparisons using matrix models were made between eight closely related species from the Calochortus genus. Results indicated that matrix models do not give a complete picture of population dynamics. Population distribution (proportion of seedlings, juveniles, and reproductive adults) were highly variable between population, habitats, and years. For most species, including C. umpquaensis, there was a lower proportion of juvenile plants than the model predicted. Reproduction was most limiting to population growth and more variable, and perhaps less predictable than was mortality. Reproductive output varied considerably across habitats (Feidler et al. 1998).

On April 4, 1996, a Conservation Agreement among the BLM, the Forest Service (FS), and the Fish and Wildlife Service (F&WS) was signed and was implemented. This agreement addressed the effects of timber harvest and cattle grazing (USFWS 2000). In 1999, between 400,000 and 800,000 C. umpquaensis individuals were estimated to occur on BLM land. These numbers are significantly higher than the 120,000 to 140,000 individuals estimated in the early 1990s. Subsequently, the Fish and Wildlife Service removed it from the list of Candidate for Endangered status. (USFWS 2000) Seed from 4 locations stored at The Berry Botanic Garden.

Continued search for new populations (Fredricks 1989) Study factors influencing limited distribution (Fredricks 1989) US Forest Service is working with landowners to adjust seasonal livestock use and fences Continued monitoring (Fredricks 1992).

Collect and store seeds from populations across the range. Determine propagation and re-introduction protocols.